Mechanical lead-pencil



. a pencil containing my invention.

UNITED STATES- FREDERICK W. MUSSON, OF CHICAGO, ILLINOIS.

M ECHANICAL LEAD-PENCIL.

SPECIFICATION forming part of Letters Patent No. 592,161, dated. October19, 1897.

, Application filed s in 6, 139 smart. 586,421. (ll'o nodelo To all whomit may concern.-

Be it known that I, FREDERICK W. MUSSON, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Pencils, of which thefollowing is a specification.

My invention relates to lead-pencils, and particularly to lead-pencilsin which the lead is movable-or adjustable, and'hasfor its object toprovide simple and convenient means whereby the lead may be extended orwithdrawn by the user as occasion may require.

I have illustrated my invention with some modifications and details, butI do not in so doing intend to be understood as saying that l have hereillustrated all forms of my invention, for I am simply endeavoring bythis means to set forth in an intelligible manner, so to speak, one formof my invention, and which form contains the principle. Of course thisprinciple will be applicable in various ways to modified forms of thedevice.

Proceeding now to describe the particular forms and features which Ihave specially illustrated, I refer to the accompanying drawings,wherein w Figure 1 is a longitudinal section through Fig. 2 is a likesection through a modification; Fig. 3, a like section through a furthermodification. Figs. 4, 5, 6, and 7 are details; Fig. 8, a section on theline 8 8 of Fig. 1. Fig. 9 is a section online 9 9 of Fig. 3. Fig. 10 isa detail of hexagonal lead and washer. Fig; 11 is a detail of squarelead and washer. Fig. 12 is a side view of threaded lead, which in thiscase is round, or approximately so.

Like parts are indicated by the same letters in all the figures.

A is a body, preferably of wood, having a central aperture, andpreferably provided with a head B. Within the aperture of this Wood bodyis the lead, which isvariously shaped-as, for example, it may be round,or oval, or hexagonal, or square, or any other shape, though, as will behereinafter explained, the preferred form issomethin g other than round.C'indicates an oval lead; C, a found lead; C a hexagonal lead; C asquare ead.

Associated with the forward end of the wood pencil proper is thepencil-tip D, having the outer portion, which terminates in a, smallaperture through which the lead passes, and the inner portion D, whichis preferably composed of spring metal and slotted so as to be capableof being forced into and then firmly held within the lower or outer endof the.

woodportion A. This tip also has the annular chamber E, which ispreferably slottedv and made of spring metal and receives the nut F,internally screw-threaded at G and milled on its periphery at H. Theannular chamber is cut away, as indicated in Fig 6, for example, so asto leave portions of the periphery of the nut F projecting, so that theycan be pressed between the thumb and finger and thus the nut be turnedwithin the annular chamber E. v

J and J are washers, which may be used, either one or both of them, inthe end of the wood or body of the pencil preferably in proximity to thetip or point. They are used in conjunction with alead having across-section other than circular and when the aperture in the body A isnot of such shape or size as to prevent the rotation of the lead. When,

howeveigthe aperture is of" the shape and size to prevent its rotation,"the washers may be dispensed with. The" lead, whatever its shape, ispreferably under most conditions smooth when applied.

A body portion with an oval aperture and a correspondingly-shaped leadis shown in Fig. 8, and a body portion with an aperture circular incross-section in combination with an oval lead is shown in Fig. 9. Inthis case, of course, the oval lead must have associated with it one ormore washers having oval apertures. In the case of the forms shown inFigs. 10 and 11 there must either be an ap erture in the body tocorrespond with the shape of the lead, so as to stop its rotation, or awasher which will accomplish that re- 'sult. In Fig. 2 I showdiagrammatically, as it were, a clamp or spring device K, which isforced against the side of the lead and thus prevents it rotating, whenneither the form of the aperture nor the washer would accom plish thatresult. The real essence of theinvention therefore consists in having alead, an aperture in which it lies, the two related or shaped orprovided with devices so that Ice the lead may reciprocate but will notrotate, and a thumb-controlled device for causing the lead toreciprocate.

As shown above, the means for holding the lead from rotating may eitherbe an aperture of the shape of the lead or washers having holes theshape of the lead, or the lead may have a clamp like K or other suchdevice to hold it from rotating. The preferred construction is an ovallead with an oval aperture and a threaded nut to engage the lead at theextremities of the long axis of its crosssection, so as to giveclearance and permit the lead cut out by the teeth of the nut to freeitself. The nut serves not only to feed the lead forward, but also togrip it and keep it from sliding longitudinally when such motion is notdesired. This device therefore serves both to feed and to grip the lead.

I claim- 1. A lead-pencil comprising amovable lead of non-circularcross-section, the case for said lead having a longitudinal bore whichis substantially of the same cross-section, to prevent rotation of thelead, said bore being enlarged at its lower end, a tip having a plaincylindrical portion fitted to the end of the case and a conical end,anut mounted in the tip near the junction of the cylindrical and conicalportions, said lower end and conical portion forming recesses to receivethe cuttings or refuse of the lead, said nut being revolved to formnotches in and move the lead, substantially as described.

2. A lead-pencil comprisinga movable lead of non-circular cross-section,a case for said lead having a longitudinal bore which is ofsubstantially the same cross-section, to prevent rotation of the lead,said bore being enlarged at its lower end, a tip havingaslottedcylindrical spring portion D, fitted within the enlarged part of thebore at the end of the case, and a nut mounted in the tip and adapted toengage the lead, and when rotated, to reciprocate it.

FREDERICK W. MUSSON.

\Vitnesses:

BERTHA C. SIMS, L. W. J OHNSTONE.

